Maybe we'll see a battle royal and the last two will wrestle a match. Could be interesting to have a tri-brand battle royal (Alright, probably just two brands since no one from ECW is really a contender outside of Morrison or Punk.). I think if they would announce something like this right now, it could spike a few buys for the PPV. Battle Royals are always fan favorites.
In this scenario, I like Orton and HHH to be the final 2, with Orton getting a not so clean win, and then leading to a program between the two. You could definitely have a pretty good battle royal by including RAW and Smackdown. You figure you throw in 20 guys and here is what you get:
HHH
Orton
Kennedy
Umaga
Jeff Hardy
Carlito
Matt Hardy
MVP
Undertaker
Benjamin
Mysterio
Kane
Finlay
Snitsky
Morrison
Big Daddy V
Hardcore Holly
Masters
Cody Rhodes
Chuck Palumbo
Obviously, there are a few holes in there, but the general idea would work very well.